Bulk metallic glasses (BMGs) and high entropy alloys (HEAs) have unique structures at the length scales of micro- and nano-metre, and exhibit unique properties, which make them potential materials for structural applications. The tensile ductility of dendrite/BMG composites can be greatly improved by Bridgman solidification. The BCC structured HEA with a composition of Ti0.5AlCoCrFeNi exhibits ultrahigh fracture strength which is competitive to most of the BMGs, moreover, the strength can be sustained at high temperatures. The phase changes of HEAs are closely related to the atomic packing efficiency (APE).